test: repair test on Windows

The test did not account for the fact that the driver is spelt
differently in some cases and may have quoting involved.

Author: compnerd

test/Driver/enable_regex_literals_flag.swift

@@ -1,7 +1,9 @@
 // RUN: %target-swiftc_driver  -enable-regex-literals -disallow-use-new-driver -driver-print-jobs  %s 2>^1 | %FileCheck %s
 // The new driver has its own test for this
+
 // REQUIRES: cplusplus_driver
-// CHECK: {{.*}}/swift-frontend -frontend{{.*}}-enable-regex-literals
+
+// CHECK: {{.*}}swift{{c|-frontend}}{{(.exe)?"?}} -frontend{{.*}}-enable-regex-literals
 
 public func foo() -> Int {
     return 42